Multiple Converging Laser Beam Apparatus and Method

Abstract

A laser head apparatus that enables the use of smaller parallel converging laser beams that create multiple smaller holes in a material followed by a larger parallel diverging laser beams that remove additional material. The laser head apparatus includes laser optics and purging nozzles. A process for removing material using the laser head apparatus includes moving the laser head apparatus to a position to generate parallel converging laser beams at a target location in the material and moving the laser head apparatus to a position to generate parallel diverging laser beams at the target location from the converging laser beams.

What is claimed is: 
     
         1 . A laser head apparatus, the apparatus comprising:
 a cylindrical housing; and   laser optics disposed in the cylindrical housing and configured to transform a laser beam into a plurality of parallel converging laser beams, each of the plurality of parallel converging laser beams converging onto a focal plane, wherein the diameter of each of each of the plurality of parallel converging laser beams is less than the diameter of the laser beam; and   a plurality of purging fluid nozzles disposed in the cylindrical housing.   
     
     
         2 . The apparatus of  claim 1 , wherein the laser optics comprise a single lens comprising a plurality of optical elements, each of the optical elements configured to transform a portion of the laser into a respective one of the plurality of parallel converging laser beams. 
     
     
         3 . The apparatus of  claim 2 , wherein the plurality of purging fluid nozzles are disposed in the single lens. 
     
     
         4 . The apparatus of  claim 1 , wherein the laser optics comprise a plurality of lenses, each of the plurality of lenses configured to transform a portion of the laser into a respective one of the plurality of parallel converging laser beams. 
     
     
         5 . The apparatus of  claim 1 , wherein the plurality of purging fluid nozzles are arranged to provide a purging fluid stream, wherein the purging fluid comprises nitrogen. 
     
     
         6 . A method for removing material using a laser, comprising:
 introducing a plurality of parallel converging laser beams to the material at a target location, the plurality of parallel converging laser beams produced by laser optics disposed in a cylindrical housing of a laser head apparatus and configured to transform a laser beam into the plurality of parallel converging laser beams, each of the plurality of parallel converging laser beams converging onto a focal plane such that the target location is located between the focal plane and the laser head apparatus;   removing a first portion of the material using the plurality of parallel converging laser beams;   introducing a plurality of parallel diverging laser beams to the material at the target location, wherein the plurality of parallel diverging laser beams are formed from the plurality of parallel converging laser beams, such that the target location is located beyond the focal plane and the plurality of parallel diverging laser beams overlap before introduction to the target location; and   removing a second portion of the material using the plurality of parallel diverging laser beams.   
     
     
         7 . The method of  claim 6 , comprising introducing a purging fluid via a plurality of purging nozzles disposed in the laser head apparatus while introducing the plurality of parallel converging laser beams. 
     
     
         8 . The method of  claim 6 , comprising introducing a purging fluid via a plurality of purging nozzles disposed in the laser head apparatus while introducing the plurality of parallel diverging laser beams. 
     
     
         9 . The method of  claim 6 , wherein introducing a plurality of parallel diverging laser beams to the material at the first target location comprises increasing a power of the laser beam. 
     
     
         10 . The method of  claim 6 , wherein removing the second portion of the material comprises moving the laser head apparatus toward the material during the removal. 
     
     
         11 . The method of  claim 6 , wherein the plurality of parallel converging laser beams is a first plurality of parallel converging laser beams, the target location is a first target location, and the focal plane is a first focal plane, the method comprising:
 introducing a second plurality of parallel converging laser beams to the material at a second target location, wherein the second plurality of parallel converging laser beams are produced by the laser head apparatus disposed in the cylindrical housing, each of the second plurality of parallel converging laser beams converging onto a second focal plane such that the second target location is located between the second focal plane and the laser head;   removing a third portion of the material using the second plurality of parallel converging laser beams.   
     
     
         12 . The method of  claim 11 , wherein the plurality of parallel diverging laser beams is a first plurality of parallel diverging laser beams, the method comprising:
 introducing a second plurality of parallel diverging laser beams to the material at the second target location, wherein the second plurality of parallel diverging laser beams are formed from the first plurality of parallel converging laser beams, such that the second target location is located beyond the second focal plane and the second plurality of parallel diverging laser beams overlap before introduction to the second target location; and   removing a fourth portion of the material using the second plurality of parallel diverging laser beams.   
     
     
         13 . The method of  claim 6 , wherein the laser optics comprise a single lens comprising a plurality of optical elements, each of the optical elements configured to transform a portion of the laser into a respective one of the plurality of parallel converging laser beams. 
     
     
         14 . The method of  claim 6 , wherein the laser optics comprise a plurality of lenses, each of the plurality of lenses configured to transform a portion of the laser into a respective one of the plurality of parallel converging laser beams. 
     
     
         15 . A system, comprising:
 a laser unit, the laser unit configured to generate a laser beam;   a fiber optic cable, the fiber optic cable optically connected to laser optics of a laser head apparatus, the fiber optic cable configured to transmit the laser beam to the laser optics to produce a plurality of parallel converging laser beams;   a purging fluid line, the purging fluid line connected to a purging fluid source and configured to supply a purging fluid to a plurality of purging fluid nozzles of the laser head apparatus; and   the laser head apparatus, comprising:
 a cylindrical housing; 
 the laser optics disposed in the cylindrical housing and configured to transform the laser beam into the plurality of parallel converging laser beams, each of the plurality of parallel converging laser beams converging onto a focal plane; and 
 the plurality of purging fluid nozzles disposed in the cylindrical housing, the plurality of purging fluid nozzles configured to distribute a purging fluid. 
   
     
     
         16 . The system of  claim 15 , wherein the laser optics comprise a single lens comprising a plurality of optical elements, each of the optical elements configured to transform a portion of the laser into a respective one of the plurality of parallel converging laser beams. 
     
     
         17 . The system of  claim 16 , wherein the plurality of purging fluid nozzles are disposed in the single lens. 
     
     
         18 . The system of  claim 15 , wherein the laser optics comprise a plurality of lenses, each of the plurality of lenses configured to transform a portion of the laser into a respective one of the plurality of parallel converging laser beams. 
     
     
         19 . The system of  claim 15 , wherein the purging fluid comprises nitrogen. 
     
     
         20 . A method for removing material using a laser, comprising:
 repeating the following operations until the material is removed:
 A) positioning a laser head apparatus such that a distance between the laser head apparatus and a target location is less than the distance between the laser head apparatus and a focal plane of a lens of the laser head; 
 B) generating a plurality of parallel converging laser beams via the laser head apparatus to contact the material; 
 C) positioning the laser head apparatus such that a distance between the laser head apparatus and the target location is greater than the distance between the laser head apparatus and the focal plane of the lens of the laser head apparatus; and 
 D) generating a plurality of parallel diverging laser beams to contact the material via the laser head apparatus, wherein the parallel diverging laser beams overlap before contacting the material.